What is the definition of breathing, external respiration, gas transport , and internal respiration ...

• Breathing: O2 into lungs(ATP) and Co2 out of lungs(waste)
• External respiration: The exchange of oxygen and carbon dioxide between the lungs and the blood.  Oxygen moves from the lungs into the blood, and carbon dioxide moves from the blood into the lungs.
• Gas transport: Transport of oxygen from the lungs to the cells and of carbon dioxide frm the cells to the lungs.
• Internal respiration: The exchange of oxygen adn carbon dioxide between the blood and the cells.  Oxygen moves from the blood to the cells, where it is used in cellular respiration to produce ATP and carbon dioxide.  Carbon dioxide produced by the cells moves into the blood.